Draft it Help

This command draws a construction line perpendicular to an existing line at a given point.

Select the button and the command prompt reads:

Give Line:

Select the line to draw perpendicular to, the command prompt reads:

Give Point:

Use any of the snaps and input options to indicate the point you wish the to draw the construction line through. A line three times the width of the current Page is drawn perpendicular to the selected line. This is drawn on a layer called 'Constructions' which is set to 'blue' by default.